Thin film transistor comprising oxide semiconductor

Abstract

Provided are a thin film transistor in which an oxide semiconductor combined with a nitride containing boron or aluminum is applied to a channel layer and a method of fabricating the same. The thin film transistor in which an oxide semiconductor combined with a nitride containing boron or aluminum is applied to a channel layer exhibits significantly improved mobility and increased stability at a high temperature.

What is claimed is: 
     
       1. A thin film transistor comprising:
 source and drain electrodes, a channel layer, a gate insulating layer and a gate electrode disposed on a substrate, 
 wherein the channel layer is formed of a semiconductor thin film that includes an oxide semiconductor combined with a nitride containing boron or aluminum, 
 wherein the nitride containing boron or aluminum is included such that the boron or aluminum exists within a range of 0.01 to 50 atomic weight percent on the basis of the total atomic weight of metal atoms of an oxide semiconductor constituting the semiconductor thin film. 
 
     
     
       2. The thin film transistor of  claim 1 , further comprising a channel protection layer formed of at least one insulating material selected from the group consisting of AlOx, SiNx and SiOx on the channel layer. 
     
     
       3. The thin film transistor of  claim 1 , wherein the thin film transistor has a top gate coplanar structure in which source and drain electrodes, a channel layer, a gate insulating layer and a gate electrode are sequentially stacked on a substrate, a top gate staggered structure in which a channel layer, source and drain electrodes, a gate insulating layer and a gate electrode are sequentially stacked on a substrate, a bottom gate coplanar structure in which a gate electrode, a gate insulating layer, source and drain electrodes and a channel layer are sequentially stacked on a substrate or a bottom gate staggered structure in which a gate electrode, a gate insulating layer, a channel layer and source and drain electrodes are sequentially stacked on a substrate. 
     
     
       4. The thin film transistor of  claim 1 , wherein the oxide semiconductor is formed of at least one selected from the group consisting of ZnO, In—Zn—O, Zn—Sn—O, In—Ga—ZnO, Zn—In—Sn—O, In—Ga—O and SnO 2 . 
     
     
       5. The thin film transistor of  claim 1 , wherein the nitride containing boron or aluminum includes BN or AlN. 
     
     
       6. The thin film transistor of  claim 1 , wherein the gate insulating layer is formed of at least one insulating material selected from the group consisting of AlOx, SiNx and SiOx. 
     
     
       7. The thin film transistor of  claim 2 , wherein the thin film transistor has a top gate coplanar structure in which source and drain electrodes, a channel layer, a gate insulating layer and a gate electrode are sequentially stacked on a substrate, a top gate staggered structure in which a channel layer, source and drain electrodes, a gate insulating layer and a gate electrode are sequentially stacked on a substrate, a bottom gate coplanar structure in which a gate electrode, a gate insulating layer, source and drain electrodes and a channel layer are sequentially stacked on a substrate or a bottom gate staggered structure in which a gate electrode, a gate insulating layer, a channel layer and source and drain electrodes are sequentially stacked on a substrate. 
     
     
       8. The thin film transistor of  claim 2 , wherein the oxide semiconductor is formed of at least one selected from the group consisting of ZnO, In—Zn—O, Zn—Sn—O, In—Ga—ZnO, Zn—In—Sn—O, In—Ga—O and SnO 2 . 
     
     
       9. The thin film transistor of  claim 2 , wherein the nitride containing boron or aluminum includes BN or AlN. 
     
     
       10. The thin film transistor of  claim 2 , wherein the gate insulating layer is formed of at least one insulating material selected from the group consisting of AlOx, SiNx and SiOx. 
     
     
       11. A thin film transistor comprising:
 source and drain electrodes, a channel layer, a gate insulating layer and a gate electrode disposed on a substrate, 
 wherein the entire channel layer comprises only mixed material formed by mixing an oxide semiconductor and a nitride, and the mixed material comes in direct contact with the gate insulating layer, and the nitride contains boron or aluminum.